1. Field of the Invention
The present invention relates to a voice recognition apparatus and a recording medium storing a voice recognition program. In particular, the present invention relates to a voice recognition apparatus and a recording medium storing a voice recognition program that extract recognition target words, which are targeted for recognition, from a plurality of words stored in a vocabulary dictionary storing unit and perform a matching processing using the extracted recognition target words.
2. Description of Related Art
Conventionally, as a means of accepting an input from a user, a voice recognition apparatus that utilizes a voice recognition engine so as to recognize a speech (a voice) of a user and accept it as an input to a system has been known. Such a voice recognition apparatus has already been commercialized in, for example, information delivery systems including a voice portal and a car navigation system.
With the expanding variety of functions (increasing number of functions) of such information delivery systems, the vocabulary targeted for recognition tends to enlarge in the information delivery systems. For example, in the case where the voice recognition apparatus is mounted in a car navigation system, the vocabulary targeted for recognition includes individual functions of operations, and the names of places and facilities throughout the country. Thus, the vocabulary targeted for recognition is huge. It is very difficult to store a huge vocabulary in a vocabulary dictionary storing unit and recognize a user's speech properly and efficiently from the vocabulary in the vocabulary dictionary storing unit.
Now, in the information delivery systems with increasing number of functions, in many cases, only part of the entire functions are actually used by users. Taking note of this fact, JP 5-61800 U discloses a technology of automatically deleting words that are stored in a vocabulary dictionary storing unit and used with a low frequency. More specifically, an erasing control unit of a voice recognition apparatus monitors whether words stored in the vocabulary dictionary storing unit are used for recognition within a count period of a timer. Then, the erasing control unit deletes the words that are not used for recognition at all within a predetermined period. This makes it possible to recognize a user's speech properly and efficiently from the vocabulary in the vocabulary dictionary storing unit.
Also, JP 9-26799 A discloses a technology of deleting words that are stored in a vocabulary dictionary storing unit and used with a low frequency. JP 9-26799 A discloses a configuration of mounting a voice recognition apparatus in a car navigation system.
However, the configurations disclosed in JP 5-61800 U and JP 9-26799 A mentioned above have the following problem. When a user uses the deleted word, for example, even when the user utters that deleted word, the voice recognition apparatus cannot recognize it because this word is already deleted from the vocabulary dictionary storing unit.
In order to solve this problem, JP 2000-259180 A discloses a technology of deleting words that are stored in a vocabulary dictionary storing unit and used with a low frequency and storing the deleted words into the vocabulary dictionary storing unit again. More specifically, a list of the deleted words is displayed on a display screen, and a user selects words to be stored in the vocabulary dictionary storing unit from among the deleted words. Then, the selected words are stored into the vocabulary dictionary storing unit again. In this manner, even when a word is once deleted and then the need to target this word for recognition arises later, it is possible to store the deleted word into the vocabulary dictionary storing unit easily.